The next time you pee, think about this: Your urine could one day create the sustainable building materials of the future. Dyllon Randall is a research engineer at the University of Cape Town. He’s also the supervisor on a new project in which students harvested urine from urinals so they could transform the waste into building bricks. Not only could these bio-bricks eliminate one form of human waste, they could also help fight climate change.
In a paper published in the Journal of Environmental Chemical Engineering, the team describes the process of creating one of its bio-bricks. First, they collect human urine in special urinals that convert much of the liquid into a solid fertiliser. Then, they add the remaining urine to lose sand they colonised with a bacteria that produces an enzyme called urease. This urease reacts with the urine over a period of four to six days, cementing the sand into the brick-like shape of its container. This whole process takes place at room temperature, while creating traditional bricks involves the use of carbon emission-producing kilns. And as yet another bonus, the team says it can convert the little bit of human urine left over from the brick-building process into yet another fertiliser.
Ultimately, this team has taken something most of us don’t think twice about flushing down the toilet every day and transformed it into two things we need: fertiliser and building materials. Still, the amount of urine needed to produce just one brick would require about 100 trips to the restroom, so unless the team is able to get its hands on a lot more urine, these bio-bricks might never find their way onto a construction site.
Science Alert, 27 October 2018 ; http://www.sciencealert.com.au